1. Field of the Invention
The present invention relates to a transmission with a planetary gear mechanism having an element adapted to be fixed to a transmission case and a method for assembling the same.
2. Description of the Related Art
In a conventional transmission of this type, when elements of the planetary gear mechanism such as the ring gear and the carrier are fixed to the transmission case, those elements are splined to the transmission case so that they do not rotate relative to the transmission case, and they are also locked with snap rings so that they do not move axially relative to the transmission case (refer to Japanese Patent Unexamined Publication No. Hei.1-203740).
In order to facilitate the assembling work of transmissions, it is a desirable sequence of assembling transmissions that the transmission constituent members including the planetary gear mechanisms are assembled on the shaft member of the transmission axially sequentially in a predetermined order in an open space outside of the transmission case, and thereafter the transmission constituent members including the planetary gear mechanisms so assembled are installed in the transmission case.
In the conventional transmission, however, in which the element to be fixed of the planetary gear mechanism is locked by the snap ring so as to prohibit the relative axial movement thereof to the transmission case, if the other transmission constituent members are present in front of the planetary gear mechanism when viewed from the side of the transmission case facing the open end thereof, these transmission constituent members hinder the snap ring mounting work. Therefore, it is not possible to subassemble the planetary gear mechanisms on the shaft member together with those transmission constituent members. As a result of this, the transmission constituent members including the planetary gear mechanisms have to be assembled sequentially in an order in which those to be situated toward the deepest end of the transmission case are first assembled, this making the assembly work of transmissions troublesome.
The present invention was made in view of the aforesaid problem and an object of thereof is to provide a transmission in which elements to be fixed of a planetary gear mechanism can be locked so as to prohibit the relative axial movement thereof to a transmission case through operations from the outer surface of a circumferential wall portion of the transmission case, whereby the assembling efficiency is improved, and a method for assembling the same.
With a view to solving the aforesaid problem, according to the present invention, there is provided a transmission, wherein a first engagement portion is provided on an element of a planetary gear mechanism to be fixed to a transmission case which is adapted to be brought into engagement with the transmission case so as to prohibit the relative rotation of the element to the transmission case, fixing members are provided which can freely be inserted into the interior of the transmission case from an outer surface of a circumferential wall portion of the transmission case, and a second engagement portion is provided on the element which is adapted to be brought into engagement with the fixing members so as to prohibit the relative axial movement of the element to the transmission case.
With a view to assembling the aforesaid transmission with good working efficiency, according to the present invention, there is provided a method for assembling the same transmission comprising the steps of assembling a plurality of transmission constituent members including the planetary gear mechanisms on a shaft member of the transmission axially sequentially in a predetermined order, thereafter installing the plurality of transmission constituent members including the planetary gear mechanisms so assembled in the transmission case, and then inserting the fixing members into the interior of the transmission case.
According to the transmission of the present invention, even if the other transmission constituent members are present in front of the planetary gear mechanism in question on the side of the transmission case facing the open end thereof, the fixing members are inserted into the interior of the transmission case from the outer surface of the circumferential wall portion of the transmission case for engagement thereof with the second engagement portions of the elements to be fixed of the planetary gear mechanisms, whereby the elements can be locked so as to prohibit the relative axial movement thereof to the transmission case.
Consequently, as with the aforesaid transmission assembling method according to the present invention, the transmission constituent members including the planetary gear mechanisms can be subassembled, thereby making it possible to improve the assembling efficiency of transmissions.